Cylinder liner support

ABSTRACT

An internal combustion engine, having a cylinder head mounted on a cylinder block, is provided with means for supporting a cylinder liner therein, which comprises a yieldable spacer for compensating for excess loads exerted on the liner imparted by torqueing of the head to the block, together with a semiresilient support sleeve, which acts as a stiff spring to accommodate thermal expansion and contraction of the cylinder liner occurring during normal operating cycles of the engine. The yieldable spacer is chevron-shaped in cross section and has a resilient annular positioner member associated therewith. Radial movement-preventing means in the form of an annular flange on the cylinder liner, closely fitted within a bore in the block, is also provided. Alternatively, the radial movement-preventing means is an annular flange on the outer periphery of the cylinder liner adjacent its topmost end, having a plurality of circumferentially-spaced slots therein, and fitted within the cylinder bore.

United States Patent Bailey et a1.

Assignee:

Filed:

CYLINDER LINER SUPPORT inventors: John M. Bailey, Dunlap; Michael K.

Stratton, Peoria; Alan W. Wells, Edelstein, all of 111.

Caterpillar Tractor Company.

Peoria, 111.

Jan. 28, 1974 Appl. No.: 437,204

Primary Examiner-Charles J. Myhre Assistant Examiner-William C, AndersonAttorney, Agent, or FirmPhillips, Moore, Weissenberger Lempio & Strabala1 1 May 13, 1975 l 5 1 ABSTRACT An internal combustion engine, having acylinder head mounted on a cylinder block, is provided with means forsupporting a cylinder liner therein, which comprises a yieldable spacerfor compensating for excess loads exerted on the liner imparted bytorqueing of the head to the block, together with a semi-resilientsupport sleeve, which acts as a stiff spring to accommodate thermalexpansion and contraction of the cylinder liner occurring during normaloperating cycles of the engine. The yieldable spacer is chevron-shapedin cross section and has a resilient annular positioner memberassociated therewith. Radial movementpreventing means in the form of anannular flange on the cylinder liner, closely fitted within a bore inthe block, is also provided. Alternatively, the radialmovement-preventing means is an annular flange on the outer periphery ofthe cylinder liner adjacent its topmost end, having a plurality ofcircumferentiallyspaced slots therein, and fitted within the cylinderbore.

6 Claims, 3 Drawing Figures 18 a M I a 20 i I 56 32 I: 38

g 34 I 1 7o 48 g E 60 l 28 TZ i L42 f 74 5o l 40 E ,lo

PATENIED 1m 1 31915 SHEET 2 OF 2 CYLINDER LINER SUPPORT BACKGROUND OFTHE INVENTION This invention relates to a cylinder liner support meansfor internal combustion engines. More particularly, this inventionrelates to such a support means comprising a yieldable spacer incombination with a somewhat resilient support sleeve, which are disposedbetween the engine block and the cylinder liner.

Currently, engine blocks utilizing cylinder liners therein are usuallyprovided with counterbores in the top deck portion of the engine blockfor receiving flanges of the cylinder liners for mounting and locationthereof. Frequently, the uppermost face of each cylinder liner flangeprojects slightly above the top deck portion plane to enable a headgasket to be compressed between the cylinder head and the cylinder linerflange and thereby provide an effective seal for combustion gasesgenerated within the cylinder. A problem arises in that, with engineshaving a plurality of cylinders and corresponding cylinder liners,machining tolerances of the counterbores and liner flanges results insome of the liners projecting above the top deck portion plane furtherthan others. When this happens, the torqueing of the head to the blockcauses liners with a greater projection to subject their respectivecounterbores to greater loads than liners having a lesser projection.The relatively high bolt torque which is required to insure adequatesealing of the head gasket often results in excess stress in thecounterbore, and during engine operation, load and thermal stressescause cracking of the block counterbores, with an accompanying loss ofliner protection and failure of the combustion seal.

In attempting to overcome these problems, some designs employ ayieldable spacer disposed between a shoulder of the cylinder liner andan annular column which is integrally cast as part of the cylinderblock, e.g. US. Pat. No. 3,628,427 issued Dec. 21, 1971 to Bailey; US.Pat. No. 3,568,573 issued Mar. 9, 1971 to Bailey et al, both of commonassignment herewith. These designs have not been entirely satisfactory,since although experimental testing has shown that such an arrangementfunctions satisfactorily, it has not proved to be practical for the massproduction of engine blocks. One of the reasons is that the integralcolumns are formed by casting around cores which are part of the castingmold for the engine block. These cores have a tendency to shift slightlyduring processing of the mold and the subsequent pouring of the casting.This results in side walls of the column being irregular after the borefor the liner is machined within the column in the block. This. in turn,causes unequal loading on the cylinder liner and results in leakagearound the seals used therewith. Another cylinder liner supportarrangement is that of utilizing a support sleeve for supporting thecylinder liner within the block, e.g. US. Pat. No. 3,481,316 issued Dec.2, 1969 to Olson et al, also of common assignment herewith. However,neither the support sleeve nor the yieldable spacer have been entirelysatisfactory as a means for supporting a cylinder liner for the aboveand other reasons. This is the case, since the support means must bothcompensate for excess loads exerted on the liner due to torqueing of thehead during assembly, as well as accommodating thermal expansion andcontraction of the cylinder liner occurring during the normal operatingcycles of the engine in a practical sense. In addition to the abovenoted problems, it is also of concern to prevent unwanted radialmovement of the cylinders in the cylinder bores which may occur.

SUMMARY AND OBJECTS OF THE INVENTION The invention provides in aninternal combustion engine having a cylinder head mounted on a cylinderblock, a means for supporting a cylinder liner. The cylinder linersupport means comprise a support sleeve circumscribing a reduceddiameter portion of the cylinder liner and a yieldable spacer alsocircumscribing the reduced diameter portion. The support sleeve andyieldable spacer accommodate excess loads on and thermal cycling of thecylinder liner. Means for preventing radial movement of the cylinderliner in the form of a radial flange are also .provided.

Accordingly, it is a primary object of this invention to provide acylinder liner support which accommodates both excess loads exerted onthe liner due to assembly of the head to the block, as well as thosecaused by thermal expansion and contraction of the cylinder liner duringnormal operating cycles of the engine.

It is a further object to provide such a device in which the yieldablespacer compensates for excess load exerted on the liner during assembly,while a semiresilient support sleeve contracting therewith accommodatesthermal expansion and contraction of the cylinder liner during normaloperating cycles of the engine.

It is a further object to provide a means for preventing radial movementof the cylinder liner with respect to the block.

Other objects of the invention will become obvious in reading thefollowing detailed description of the invention.

BRIEF DESCRIPTION FIG. 1 is an enlarged cross-sectional verticalelevation view ofa cylinder liner support and means for preventingradial movement of this invention shown in an internal combustionengine;

FIG. 2 is an alternate embodiment of the device shown in FIG. 1, whichdiffers only in having an alternate means for preventing radialmisalignment; and,

FIG. 3 is a cross-sectional view taken along lines 11-11 in FIG. 2.

DETAILED DESCRIPTION Referring now to FIG. 1, a cylinder liner supportmeans of this invention is shown generally at 10, within an internalcombustion engine partially shown at 12. The engine comprises a headportion partially shown at 14 mounted on an engine block, partiallyshown at 16. Intermediate the head portion 14 and the top deck portion18 of the engine block 16 is a head gasket 20. Other than the top deckportion, the engine block includes a lower wall 22 which partiallydefines a crankcase cavity 24 for containing the crankshaft partiallyshown at 26. The engine block also includes a cast shelf 28 disposedintermediate the top deck portion 16 and lower wall portion 22. Acylinder bore 30 is formed within the block by a plurality of concentricbores 32, 34 and 36 individually formed in the top deck, cast shelf, andlower wall, respectively. Received within the bores in close-fittingrelation therewith is a cylinder liner 38 of generally cylindricalconfiguration, having a reduced diameter portion 40 at the lower endthereof which defines an annular shoulder 42 therearound. A secondreduced diameter portion 44 is provided at the lowermost end of thecylinder liner 38. The liner itself defines a piston bore 46 forreciprocatingly conataining piston 48 which is connected to connectingrod 50. A counterbore 52 is contained in lower wall 22 and de fines aradially extending shelf 54.

A plurality of coolant passages 56 are formed in top deck portion 18 inalignment with similar passages 58 in the cylinder head and gasket 14and 20. Additional passages 60 are formed in the cast shelf 28. Thecylinder head 14 is secured to the engine block by conventional meanssuch as bolts (not shown).

The cylinder liner 38, which may be of cast iron, extends through bores32, 34 and 36 to form a pair of annular coolant cavities 62, 64circumscribing a cylinder liner on opposite sides of cast shelf 28. Anannular re cess 66 is provided on the uppermost end of the cylinderliner adjacent to the cylinder head 14 for the purpose of receiving amatching portion of the head gasket for sealingly separating the coolantfrom combustion chamber 68 formed by head 14, piston 48 and cylinderliner 38. Intermediate the upper and lower ends of the cylinder liner isa radially extending annular flange 70, closely fitted within bore 34for the purpose of preventing radial movement of the liner.

The cylinder liner support means 10 comprises a similar resilientsupport sleeve 72 circumscribing a reduced diameter portion 40 of thecylinder liner. Support sleeve 72 has a peripheral groove 74 therearoundand is relatively thin compared to the thickness of the cylinder liner.The sleeve, which may be made of metal, is relatively thin-walled sothat it has a lower spring rate relative to the thicker cylinder liner.

The support means further comprises a chevronshaped yieldable spacer 76which may be made of resilient material. Disposed between the spacer andthe cylinder liner is a resilient annular ring member 78, which may bemade of rubber or other resilient material, for the purpose of radiallypositioning the spacer. The spacer also serves as a seal to preventcoolant from entering the crankcase cavity 24.

In operation, when the cylinder head 14 is torqued on to the engineblock 16, the load is applied to the cylinder liner through head gasket20. The load is transmitted through to the support sleeve 72, whichcauses the support sleeve to be slightly, axially compressed, as well asthe yieldable spacer 76 yielding at a predetermined load. Furthertightening of the cylinder head to the block will cause the spacer tocontinue to yield without significantly increasing the load on supportsleeve 72 or cylinder liner 38. When the engine is fully operating,coolant flowing through cavity 64, passages 60, cavity 62 and passages56 and 58 flows into the cylinder head 14. Heat generated through theengine operation will cause the cylinder liner to expand axially furtherdeforming the yieldable spacer 76 which takes a permanent set in theyielded position. However, since the predetermined yield point of thespacer has created a compressed condition of the support sleeve, thesleeve acts as a stiff spring and serves to continuously urge the lineragainst the head gasket as the engine cools and the liner contracts.This stiff spring effect causes the support sleeve to act in a resilientmanner.

Turning to FIGS. 2 and 3, there is therein illustrated an alternateembodiment which differs from the primary embodiment shown in FIG. 1only in that the radial movement of the liner is prevented in adifferent manner. With this embodiment, no intermediate cast shelf isprovided. Rather, radial movement is prevented by an annular guideflange 80 on the outer periphery of the cylinder liner 38' adjacent toits topmost end. This flange 80 is closely fitted within bore 32,adjacent top deck portion 18. In order to permit coolant in cavity 62'to flow freely, a plurality of axially aligned, circumferentially spacedslots 82 are formed in the flange 80 to permit free coolant flow topassages 56 and 58, in the top deck and head portions, respectively.

Although the invention has been described in terms of specificembodiments, it is apparent that other embodiments may be resulted towithout departing from the spirit and scope of this invention. Thus, theinven tion is not to be otherwise limited, except as specificallypointed out in the claims hereto appended.

What is claimed is:

1. In an internal combustion engine, a cylinder head mounted on acylinder block, said block defining a top deck portion, a cylinder borein said cylinder block, a generally cylindrical cylinder liner disposedwithin said cylinder bore, a reduced diameter portion of said cylinderliner defining an annular shoulder intermediate said top deck and saidshelf, means for supporting said cylinder liner comprising a supportsleeve circumscribing said reduced diameter portion of said cylinderliner having an end thereof in abutment with said annular shoulder,wherein said support sleeve is relatively thin walled with respect tosaid cylinder liner whereby it possesses a relatively lower spring ratewith respect to said sleeve, and further including means for preventingradial movement of said cylinder liner in said block comprising a shelfin said block intermediate said top deck and lower wall defining a bore,and an annular flange on said cylinder liner closely fitted within saidlast-named bore.

2. In an internal combustion engine, a cylinder head mounted on acylinder block, said block defining a top deck portion, a cylinder borein said cylinder block, a cavity in said block including a lower walldefining a shelf located intermediate the top deck and the lower wall, agenerally cylindrical cylinder liner disposed within said cylinder bore,a reduced diameter portion of said cylinder liner defining an annularshoulder intermediate said top deck and said shelf and means forsupporting said cylinder liner comprising a support sleevecircumscribing said reduced diameter portion of said cylinder linerhaving an end thereof in abutment with said annular shoulder, and ayieldable spacer circumscribing said reduced diameter portion and inabutment with the other end of said support sleeve and said shelfwhereby excess loads on and thermal cycling of said cylinder liner areaccommodated, wherein said support sleeve is relatively thin walled withrespect to said cylinder liner whereby it possesses a relatively lowerspring rate with respect to said sleeve, and further including aresilient annular member disposed between said reduced diameter portionof said liner and said yieldable spacer so as to radially position saidspacer.

3. The invention of claim 1 wherein said yieldable spacer ischevron-shaped in cross-section.

4. The invention of claim 1 wherein said shelf is formed in acounterbore in said lower wall whereby said yieldable spacer is fittedwithin said counterbore.

6. The invention of claim 5 wherein said annular guide flange has aplurality of circumferentially-spaced slots therein.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3 8828Lr2 DATED I May 13, 1975 INVENTOR( I John M. Bailey, et al It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

On the Title Page, Item [73], change the spelling of the assignee'scorporate name from "Caterpillar Tractor Company" to --CaterpillarTractor Co.-.

Signed and Scaled this twenty-eight Day Of October 1975 [SEAL] Attest:

RUTH c. MASON C. MARSHALL DANN Arresting Office) Commissioner ufPatenlsand Trademarkx

1. In an internal combustion engine, a cylinder head mounted on acylinder block, said block defining a top deck portion, a cylinder borein said cylinder block, a generally cylindrical cylinder liner disposedwithin said cylinder bore, a reduced diameter portion of said cylinderliner defining an annular shoulder intermediate said top deck and saidshelf, means for supporting said cylinder liner comprising a supportsleeve circumscribing said reduced diameter portion of said cylinderliner having an end thereof in abutment with said annular shoulder,wherein said support sleeve is relatively thin walled with respect tosaid cylinder liner whereby it possesses a relatively lower spring ratewith respect to said sleeve, and further including means for preventingradial movement of said cylinder liner in said block comprising a shelfin said block intermediate said top deck and lower wall defining a bore,and an annular flange on said cylinder liner closely fitted within saidlast-named bore.
 2. In an internal combustion engine, a cylinder headmounted on a cylinder block, said block defining a top deck portion, acylinder bore in said cylinder block, a cavity in said block including alower wall defining a shelf located intermediate the top deck and thelower wall, a generally cylindrical cylinder liner disposed within saidcylinder bore, a reduced diameter portion of said cylinder linerdefining an annular shoulder intermediate said top deck and said shelfand means for supporting said cylinder liner comprising a support sleevecircumscribing said reduced diameter portion of said cylinder linerhaving an end thereof in abutment with said annular shoulder, and ayieldable spacer circumscribing said reduced diameter portion and inabutment with the other end of said support sleeve and said shelfwhereby excess loads on and thermal cycling of said cylinder liner areaccommodated, wherein said support sleeve is relatively thin walled withrespect to said cylinder liner whereby it possesses a relatively lowerspring rate with respect to said sleeve, and further including aresilient annular member disposed between said reduced diameter portionof said liner and said yieldable spacer so as to radially position saidspacer.
 3. The invention of claim 1 wherein said yieldable spacer ischevron-shaped in cross-section.
 4. The invention of claim 1 whereinsaid shelf is formed in a counterbore in said lower wall whereby saidyieldable spacer is fitted within said counterbore.
 5. The invention ofclaim 1 wherein said radial movement-preventing means comprises anannular guide flange on the outer periphery of said cylinder lineradjacent to its uppermost end, said guide flange being closely fittedwithin said cylinder bore.
 6. The invention of claim 5 wherein saidannular guide flange has a plurality of circumferentially-spaced slotstherein.